1. Field of the Invention
This invention relates generally to keys with built-in remote controls.
2. Prior Art
Many automobiles are provided with door locks operable with a key, and also with a remote control built into the head of the key. Because the remote control circuitry is expensive, some remote control keys have shafts which are separable from the heads, so that the heads can be used for different vehicles by changing the shafts.
For example, U.S. Pat. No. 5,331,325 to Miller shows a key with a hollow head which houses remote control circuitry. The head is comprised of two halves that are fastened together by removable screws. A shaft is secured to an integral socket at the base of the head by some of the screws. The two halves of the head must be separated to change the shaft. Since the shaft is secured by conventional screws, it can be detached by a consumer, who might not be competent to replace key shafts. Further, the integral shaft socket on the head is made of the same material as the rest of the head, which in practice must be plastic, so that the socket is relatively weak. The head might break off from the shaft if a moderate force is applied to the head when the key is in a keyhole. Due to the small size of the circuit board inside the head, there is no room to provide a printed antenna on the circuit board. Therefore, the metal shaft is used as an antenna. The shaft is attached to the circuit board by a conductive pad on the end of a lead wire. The contact between the shaft and the pad is made without solder, so that it may corrode and reduce transmit power. The assembly of the lead wire, conductive pad, and the shaft is also relatively labor intensive.
U.S. Pat. No. 5,592,169 to Nakamura et al. shows a remote control key comprising a T-shaped shaft with a transverse member positioned in an integral socket in a hollow head. The shaft is only replaceable by disassembling the head. Also, the socket is made of the same material as the rest of the head, which must be plastic, so that the socket is too weak to hold the shaft reliably. U.S. Pat. No. 4,998,952 to Hyatt, Jr. et al. shows an electronic key with a hook-shaped proximal end wrapped around an electronic housing, which is secured by a pin extending through it and the shaft of the key. However, the odd shape of the key may reduce consumer acceptance.
Accordingly, objects of the present mechanical and remote control key are:
to include a shaft for operating a mechanical lock;
to include a head with remote control circuitry for operating a remote control lock;
to enable the shaft to be detached from the head without disassembling the head;
to prevent the shaft from being easily detached from the head by a consumer;
to provide a strong and reliable attachment between the shaft and the head; and
to include an internal antenna inside the head.
Further objects of the present invention will become apparent from a consideration of the drawings and ensuing description.
The present mechanical and remote control key includes a hollow head comprised of two separable halves. A T-shaped metal socket is attached to the head. A transverse member of the socket is secured inside the head, and a longitudinal member of the socket extends outwardly through a hole at the base of the head. A proximal end of a metal shaft is inserted into a slot in the longitudinal member of the socket. The shaft is secured in the socket by a pin staked through the longitudinal member of the socket and positioned along a channel at the proximal end of the shaft. Remote control electronic components are arranged on a first circuit board inside the head, and a printed antenna is arranged on a second circuit board stacked with and electrically connected to the first circuit board.